EL Flashcards
Titration of Iodine Thiosulfate
STAGE 1- use a sample of oxidising agent to oxidise as much iodide as possible
STAGE 2- Find out how many moles of iodine have been produced
STAGE 3- METHOD
Put all the solution produced in Stage 1 in a flask.
2) From the burette, add sodium thiosulfate solution to the solution in the flask.
3) 3) It’s hard to see the end point, so when the iodine colour fades to pale yellow, add 2 cm? of starch solution as an indicator (to detect the presence of iodine). The solution in the conical flask will go dark blue, showing there’s still some iodine in there.
) Add sodium thiosulfate one drop at a time until the blue colour disappears. When this happens, it means all the iodine has just reacted, ) Now you can calculate the number of moles of iodine in the solution.
